from django.test import TestCase

# Create your tests here.

def setToStr(aSet):
    return "-".join(aSet)

def strToSet(aStr):
    if len(aStr) == 0:
        return set()
    s = aStr.split("-")
    return set(s)

a = "1-2-3-4"
aa = "1-2-5-6-4-1"
b = strToSet(a)
bb = strToSet(aa)

c = bb.difference(b)

for s in c:
    print(s + "++")

print(c)